I have tried to make a glass vial keepsake pendant that includes water. The water is the most important component, as that's what I'm trying to save. I'm a disney freak, and I am trying to keep some water from the pirates of the carribean ride, so i assume the water is chlorinated.I did some googling and all I could find was to add a drop of oil to the top and seal the vial lid.I did this and the water is still evaporating quite fast.Is there something I can add to the water to make it stop evaporating, or slow it down?

If the top is cork, it can be porous, especially if it dries, or was punctured by a hanger, and there may be minute gaps or leaks when the cork is in, esp. So you need to find a way to make an airtight seal. What about sealing some wax, or resin, around the top and cork?